Hand exerciser



FIG. 1 is a front perspective view of a hand exerciser shown in a partially disassembled state showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a front end view thereof; and,

FIG. 6 is a rear end view thereof. 

The ornamental design for a hand exerciser, as shown. 